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Description:Paleobiology, founded to provide a forum for the greater integration
of paleontology and biology, began publication in 1975. Paleobiology publishes
original articles that emphasize biological or paleobiological processes and
patterns including: speciation, extinction, development of individuals and colonies,
natural selection, evolution, and patterns of variation, abundance and distribution
of organisms in space and time. Papers concerning recent organisms and systems
are also included if they aid in understanding the fossil record and the history
of life. In addition to research articles of moderate length, Paleobiology provides
an outlet for shorter and longer pieces. The Matters of the Record section features
succinct, up-to-date discussions of new discoveries, reviews of recent conceptual
advances, and brief syntheses of important topics. Paleobiology also
publishes short book essays in its Book Review section. In 1999 Paleobiology began
publication of an occasional series, Paleobiology Memoirs, which
provides an outlet for longer works on the same topics covered in regular research
articles.

The "moving wall" represents the time period between the last issue
available in JSTOR and the most recently published issue of a journal.
Moving walls are generally represented in years. In rare instances, a
publisher has elected to have a "zero" moving wall, so their current
issues are available in JSTOR shortly after publication.
Note: In calculating the moving wall, the current year is not counted.
For example, if the current year is 2008 and a journal has a 5 year
moving wall, articles from the year 2002 are available.

Terms Related to the Moving Wall

Fixed walls: Journals with no new volumes being added to the archive.

Absorbed: Journals that are combined with another title.

Complete: Journals that are no longer published or that have been
combined with another title.

Abstract

Hierarchy is a central phenomenon of life. Yet it does not feature as such in traditional biological theory. The genealogical hierarchy is a nested organization of entities at ascending levels. There are phenomena common to all levels: (1) Entities such as genomic constituents, organisms, demes, and species are individuals. (2) They have aggregate characters (statistics of characters of subparts), but also emergent characters (arising from organization among subparts). Character variation changes by (3) introduction of novelty and (4) sorting by differential birth and death. Causation of introduction and sorting of variation at each level may be (5) upward from lower levels, (6) downward from higher levels, or (7) lodged at the focal level. The term "selection" applies to only one of the possible processes which cause sorting at a focal level. Neo-Darwinian explanations are too narrow, both in the levels (of genotypes and phenotypes) and in the directive process (selection) which are stressed. The acknowledgment of additional, hierarchical phenomena does not usually extend beyond lip service. We urge that interlevel causation should feature centrally in explanatory hypotheses of evolution. For instance, a ready explanation for divergence in populations is "selection of random mutants." But upward causation from genome dynamics (or downward causation from the hierarchical organism) to the directed introduction of mutants may be more important in a given case. Similarly, a long-term trend is traditionally explained as additive evolution in populations. But sorting among species may be the cardinal factor, and the cause may not be species selection but upward causation from lower levels. A general theory of biology is a theory of hierarchical levels-how they arise and interact. This is a preliminary contribution mainly to the latter question.